AU2002213921B8

AU2002213921B8 - Herbicidal compositions

Info

Publication number: AU2002213921B8
Application number: AU2002213921A
Authority: AU
Inventors: Ken Pallett; Ashley Slater
Original assignee: Merial Ltd
Current assignee: Merial Ltd
Priority date: 2000-09-18
Filing date: 2001-09-17
Publication date: 2006-05-25
Anticipated expiration: 2021-09-17
Also published as: CA2422189C; AU2002213921B2; ZA200301848B; MXPA03002356A; US20040072691A1; DE60115694T2; BR0113948A; ATE311747T1; GB0022833D0; RU2304389C2; CN1235474C; WO2002021922A1; DK1330162T3; EP1330162B1; EP1330162A1; ES2254514T3; AU1392102A; US6878675B2; CN1458824A; DE60115694D1

Abstract

The invention relates to a composition comprising (a) 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3-cyclohexanedione, or an agriculturally acceptable salt or metal complex thereof; and (b) N-isopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-4-(4'-fluoro-oxycetanilide); and their use as herbicides.

Description

WO 02/21922 PCT/EP01/10693 HERBICIDAL COMPOSITIONS New Herbicidal Compositions This invention relates to new compositions comprising an N-isopropylheteroaryloxyacetanilide herbicide and a benzoyl cyclohexanedione derivative, and to their use as herbicides.

The compounds of the invention are known in the art.

N-lsopropylheteroaryloxyacetanilides are described in European Patent Publication Number 0348737, published on 3 January 1990, which in particular discloses Nisopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-(4'-fluoro-oxyacetanilide) as compound 34. Benzoyl cyclohexanediones are described in for example European Patent Publication No. 0186118. U.S. Patent Publication No. 5,506,196, specifically discloses 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3-cyclohexanedione. Both of these publications teach that these compounds possess herbicidal activity. However, neither of the publications teach specific anti-gramineous properties in the compounds. EP-A1-0348737 teaches that the acetanilide compounds may be applied at from 0.01 to 10 kg of active compound per hectare of soil surface, preferably 0.05 to 5 kg per ha; no details of the precise dose rates used for the application of the compounds to treat graminea. U.S. 5,506,196 teaches that the compounds of the invention possess high activity in comparison with known compounds against certain weed species.

Hence the literature does not teach mixtures of these compounds; nor does it suggest that such a mixture would be expected to be particularly useful as an antigraminicide. At present the most commonly used mixture in this area of weed science comprises metolachlor and atrazine. These are frequently recommended for use at dose rates from 1 to 2.5 kg/ha of metolachlor and from 0.5 to 2.5 kglha of atrazine. An object of the invention is thus to provide a mixture suitable as a graminicide which may be used at reduced dose rates of active compound in comparison with the known products.

CONFIRMATION COPY WO 02/21922 PCT/EP01/10693 2 It has been found that the mixture of N-isopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2yl)-4-(4'-fluoro-oxyacetanilide) with 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3cyclohexanedione provides effective control of an extremely wide range of both monocotyledon and dicotyledon weeds at reduced dose rates when compared with these known compounds. Moreover it provides effective control together with selectivity in important crop species such as maize.

In addition to this, it has been found that in certain conditions the combined herbicidal activity of 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3-cyclohexanedione with N-isopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-4-(4'-fluoro-oxyacetanilide) for the control of certain weed species e.g. Setaria viridis, Echinochloa crus-galli, Amaranthus retroflexus and Polygonum lapathifolium, is greater than expected, without an unacceptable increase in crop phytotoxicity.

This unexpected effect gives improved reliability in controlling these competitive weeds of many crop species, and contributes to a considerable reduction in the amount of active ingredient required for weed control.

According to the present invention there is provided a method for controlling the growth of weeds at a locus which comprises applying to said locus a herbicidally effective amount of: a benzoyl cyclohexanedione of formula O O NO 2 1 0

S(O)

2

CH

3 which is 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3-cyclohexanedione or an agriculturally acceptable salt of metal complex thereof; and WO 02/21922 PCT/EP01/10693 3 N-isopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-4-(4'-fluoro-oxyacetanilide) having the formula (II):

CH(CH)

2

N-N

FC.S OIIN F() For convenience N-isopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-4-(4'-fluorooxyacetanilide) is hereafter referred to as compound B.

The amounts of 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3-cyclohexanedione and compound B applied vary depending on the weeds present and their population, the compositions used, the timing of the application, the climatic and edaphic conditions, and (when used to control the growth of weeds in crop growing areas) the crop to be treated. In general, taking these factors into account, application rates from 0.5g to 512 g of benzoyl cyclohexanedione and from 10 to 10000 g of compound B per hectare give good results. However, it will be understood that higher or lower application rates may be used, depending upon the problem of weed control encountered.

The method of the invention is most preferably used for the control of weeds at a locus used, or to be used for the growing of a crop. When applied to a crop-growing area, the rate of application should be sufficient to control the growth of weeds without causing substantial permanent damage to the crop.

Crops which the mixture may be used with include soyabeans, sugarcane, cotton, maize, sunflower, peas, chickpeas, potatoes, sorghum rice and cereals. The preferred crop, in terms of the selectivity of the mixture, is maize. For the selective control of weeds at a locus of weed infestation which is an area used, or to be used, for growing of crops application, rates from 5 g to 512 g of benzoyl cyclohexanedione and from 50 to 5000 g of compound B per hectare are particularly suitable, WO 02/21922 PCT/EP01/10693 4 preferably from 20 g to 200 g of benzoyl cyclohexanedione and from 80 g to 875 g of compound B per hectare, most preferably from 25 g to 150 g (about 80 g being most preferred) of benzoyl cyclohexanedione and from 300 g to 500 g (360 g being most preferred under humid conditions and 450 g under more dry conditions) of compound B per hectare.

The mixture is preferably applied pre-emergence but can also be applied postemergence (especially at an early stage of weed growth). By the term 'preemergence application' is meant application to the soil in which the weed seeds or seedlings are present before emergence of the crop. One example of a preemergence application is known as 'pre-plant incorporated' (PPI), where the herbicide is incorporated into the soil before planting the crop. Early PPI application may also be used. The mixture may also be applied pre-planting before the crop is planted) either to the surface of the soil or soil-incorporated. Early pre-plant treatments using the mixture (particularly surface applied) are also a feature of the method of the invention.

According to a further feature of the present invention there are provided herbicidal compositions comprising: 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3-cyclohexanedione or an agriculturally acceptable salt or metal complex thereof; and N-isopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-4-(4'-fluorooxyacetanilide); in association with, and preferably homogeneously dispersed in, a herbicidally acceptable diluent or carrier and/or surface active agent.

The term "herbicidal composition" is used in a broad sense, to include not only compositions which are ready for use as herbicides but also concentrates which must be diluted before use. Preferably, the compositions contain from 0.05 to by weight of benzoyl -1,3-cyclohexanedione and compound B.

Unless otherwise stated, the percentages and ratios appearing in this specification are by weight.

WO 02/21922 PCT/EP01/10693 Generally a composition in which the ratio of is from 1:20000 to 50:1 wt/wt (or from 1:20000 to 51.2:1 wtlwt) is used, proportions from 1000:1 to 10:1 wt/wt (or from 1000:1 to 10.24:1 wt/wt) being preferred, with proportions from 1:45 to 2.5:1 wt/wt (or from 1:43.75 to 2.5:1 wt/wt) being more preferred, and proportions from 1:20 to 2:1 wt/wt being especially preferred; ratios of 1:14 to 1:16 wt/wt (or of about 1:14.4 wt/wt) in humid conditions and of 1:17 to 1:20 wt/wt (or of about 1:18 wt/wt) in dry conditions being most preferred.

The preferred formulation according to the invention is in the form of a water dispersible granule, although it will be understood that other formulation types known in the art may also be used.

In accordance with the usual practice, a tank mix may be prepared prior to use by combining separate formulations of the individual herbicidal components.

According to a further feature of the present invention, there is provided a product comprising: 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3-cyclohexanedione or an agriculturally acceptable salt or metal complex thereof; and N-isopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-4-(4'-fluorooxyacetanilide); as a combined preparation for simultaneous, separate or sequential use in controlling the growth of weeds at a locus.

The following non-limiting experiments illustrate the present invention.

Experiment 1 Seed of various broad-leaf and grass weed species were sown in unsterilised clay loam soil. The soil surface was then sprayed with ranges of concentrations of either the individual herbicide or mixtures of the two herbicides in various proportions dissolved in a mixture of acetone and water. The said wees are Abutilon theophrasti, Amaranthus retroflexus, Chenopodium album, Digitaria sanguinalis, Echinochloa crus-galli, Ipomoea lacunosa, Panicum miliaceum, Polygonum convolvulus, Polygonum lapathifolium, Setaria faberi, Setaria viridis, Sorghum vulgare and Xanthium strumarium.

Two weeks after treatment the percent reduction in plant growth, compared to an untreated control, was assessed.

EXPERIMENT 2 Seed of various weed species, as listed in Example 1, were sown and grown up to a 1-3 leaves stage. Post-emergence applications of a range of concentrations of either the individual herbicide or mixtures of two herbicides in various proportions dissolved in a mixture of acetone and water were made.

In both cases an effective level of weed control against a number of weed species, a substantially reduced application rates of active ingredient was observed.

Comprises/comprising and grammatical variations thereof when used in this specification are to be taken to specify the presence of stated features, integers, steps or components or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

Claims

1. A method for controlling the growth of weeds at a locus which comprises applying to said locus a herbicidally effective amount of:

2-(2'-nitro-4'-methylsulfonylbenzoyl)- I 3-cyclohexanedione or an agriculturally acceptable salt or metal complex thereof; and N-isopropyl-(5-trifluoromethyl-113 ,4-thiadiazol-2-yl)-4-(4'-fluoro-oxyacetanilide) having the formula (11): CH(CH 3 )A N-N F3C S Oy 0F 2. The method according to claim 1 using an application rate of from 0.5 g to 512 g per hectare of 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3-cyclohexanedione and from 10 to 10000 g per hectare of N-isopropyl-(5-trifluoromethyl-1 ,3,4-thiadiazol-2- yl)-4-(4'-fluoro-oxyacetanilide).

3. The method according to claim 1 or 2 wherein the locus is used, or to be used, for the growing of a crop.

4. The method according to claim 3 wherein the crop is maize.

The method according to any one of the preceding claims using an application rate of from 5 g to 512 g per hectare of 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1 ,3- cyclohexanedione and from 50 g to 5000 g per hectare of trifluoromethyl-1 ,3,4-thiadiazol-2-yl)-4-(4'-fluoro-oxyacetanilide).

6. The method according to any one of the preceding claims using an application rate from 20 g to 200 g per hectare of 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1 -1,3- WO 02/21922 PCT/EP01/10693 8 cyclohexanedione and from 80 to 875 g per hectare of 1,3,4-thiadiazol-2-yl)-4-(4'-fluoro-oxyacetanilide).

7. The method according to any one of the preceding claims using an application rate of from 25 to 150 g per hectare of 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3- cyclohexanedione and from 300 to 500 g per hectare of trifluoromethyl-1,3,4-thiadiazol-2-yl)-4-(4'-fluoro-oxyacetanilide).

8. The method according to any one of the preceding claims by pre-emergence application.

9. A herbicidal composition comprising: 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3-cyclohexanedione or an agriculturally acceptable salt or metal complex thereof; and N-isopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-4-(4'-fluoro- oxyacetanilide); in association with a herbicidally acceptable diluent or carrier and/or surface active agent.

The composition according to claim 9 in which from 1:20,000 to 55:1.

11. The composition according to claim 9 in which from 1:1000 to 10:1.

12. The composition according to claim 9 in which from 1:45 to 2.5:1. the weight ratio of is the weight ratio of is the weight ratio of is

13. The composition according to claim 9 in which the weight ratio of is from 1:20 to 2:1. 9 NO

14. The composition according to any one of claims 9 to 13 in the form of a Swater dispersible granule.

A product comprising a herbicidally effective amount of: a) 2-(2'-nitro-4'-methylsulfonylbenzoyl)-1,3-cyclohexanedione or an agriculturally acceptable salt or metal complex thereof; and b) N-isopropyl-(5-trifluoromethyl-1,3,4-thiadiazol-2-yl)-4-(4'-fluoro- oxyacetanilide); cl as a combined preparation for simultaneous, separate or sequential use in O controlling the growth of weeds at a locus, wherein said product is so configured to ensure mixing of each of the components on use.

16. A method according to claim 1 substantially as hereinbefore described with reference to either of the Experiments.

17. A composition according to claim 9 substantially as hereinbefore described. DATED this 28th day of March 2006 BAYER CROPSCIENCE S.A. WATERMARK PATENT TRADE MARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA P22529AU00